This disclosure relates to a tool connection release system for one or more pieces of equipment that may be positioned in a borehole, a well, subsea, or other environment that allows the disconnection of various connections (e.g., electrical, hydraulic, optical, and/or multi-connector) in a high pressure environment. More particularly, this disclosure relates to systems for hydraulically disconnecting a tool independent of the environmental pressure. The systems may also include a secondary release mechanism.
Traditionally, if a tool package suspended from an armored or coiled tubing umbilical is to be recovered, the tool is released to allow heavy lift capable equipment using a retrieval string to be deployed to recover the tool. For hydraulic release of the tool, a piston would have to overcome the external pressure in the well, which can be as high as 24,000 psi or more. This high pressure then may lead the line pressure to be higher than the external pressure to allow actuation of the piston. Shear pins have also been conventionally used as a disconnection means, but shear pins are delicate and typically highly loaded, and can suffer fracture due to fatigue or localized corrosion from stress corrosion cracking.